OPINION:
Labour leader David Cunliffe has been crowing about the growing number of National MPs who have decided to stand down in 2014, likening it to rats deserting a sinking ship. Instead of seeking to make political capital out of his opponent's obvious drive to bring in new talent at the next election, he would do better to follow suit and start sending the underperformers and time-servers in his own caucus the message that it is time to move on.

Rejuvenation is critical to all political parties. It allows them to bring in new blood to remain fresh in the eyes of voters. However, all too often it is not the parties themselves that do the job, but the electorate, via crushing defeats which see large numbers of sitting MPs turfed out of Parliament.

That is what is so significant about the rejuvenation underway in National. So far, seven of its 59 MPs - nearly an eighth of its caucus - have indicated they will not seek re-election, and there was talk last week that up to six more are considering whether to stand again.

In many cases, those who have gone have seen the writing on the wall and realise they would only be benchwarmers in any future government John Key might lead. Kate Wilkinson and Phil Heatley, for example, were left in no doubt they would see out their parliamentary careers on the back benches when they were unceremoniously dumped as ministers in January, while Paul Hutchinson, Cam Calder and Chris Auchinvole have either worked out for themselves that it is time to move on or have been given a gentle nudge.

The departure of as many as a dozen National MPs will allow the party to bring in new faces with new ideas. Not all will succeed - politics is not for everyone, and many who arrive in Parliament soon learn they are not cut out for it - but some will instantly stamp their mark, as Steven Joyce did in 2008.

While National weeds out its underperformers, Labour is steering an altogether different course. So far, the only MP from its side of the House that has announced his retirement is Ross Robertson.

Mr Cunliffe says he is yet to speak to his MPs about their plans, but they are conversations he should start now. Darien Fenton, Moana Mackey, Rajen Prasad and Raymond Huo, who have not fired a shot since coming into Parliament and who would not be considered for ministerial posts should Labour win next year, should be among the first called into his office.

Mr Cunliffe insists that Labour's rise in the polls will give it a dozen new MPs in 2014 anyway, so its need to farewell old faces is not as urgent. That might be so, but Labour's selection process, which puts gender, ethnicity, sexual orientation and factional loyalty ahead of ability, will militate against the need to bring in some new talent, just as it saw the promising new MPs Kelvin Davis and Stuart Nash ranked below dead wood non-performers in 2011.